Freezer plate



Jan. 16, 1951 Filed May 5, 1947 H. W. KLEIST FREEZER PLATE 2 Sheets-Sheet 1 H. W. KLEIST FREEZER PLATE Jan. 16, 1951 2 SheetsSheet 2 Filed May 5, l9

r s i e ww MN m aw m ww z n N L I k wk W k Nu a 2 n I a H, WW h uuuw wuuuw uuu quvuumv v I W J i L p m h w M 6 W m m M i\\\\\\\\\\b.\\\\\\\\\\fl\\\\ k m K hm V SW W M w S W q 6% H Patented Jan. 16, 19 51 FREEZER PLATE Herman W. Kleist, Chicago, Ill., assign'or to Dole Refrigerating Company, Chicago, 11]., a corporation of Illinois Application May 5, 1947, Serial No. 745,929

My invention relates to an improvement in refrigerator plates, and has for one purpose to provide an improved plate for supporting food, for example, during the freezing process.

Another purpose is to provide a plate which may be made in substantial lengths, while maintaining true plane surfaces on both sides of the plate.

Another purpose is to provide a vacuum plate having an improved header and evaporator duct or tube structure.

Another purpose is to provide a plate of the type above described, which includes integral reenforcing means along opposite edges.

Another purpose is to provide a plate particularly adapted for the freezin of materials, such as foodstuffs, and for the handling or movement of materials during or in connection with the freezing operation.

Another purpose is to provide a-plate particularly adapted for use with materials which are moved longitudinally along the plate.

Other purposes will appear from time to time in the course of the specification and claims.

The present application is an improvement on the structure of my co-pending application 655,-

338. filed March 18, 1946, and now issued Patent I illustrate my invention more or less diagrammatically in the accompanying drawings wherein:

Figure l is a plan view with parts broken away and parts in section;

Figure 2 is an end elevation of a plate;

Figure 3 is an enlarged section taken on line 33 of Figure 1;

Figure 4 is a partial side elevation on an enlarged scale;

Figure 5 is an enlarged section taken on line 55 of Figure 1 and Figure 6 is a partial section illustrating a variant form.

Referring to the drawings, I illustrate a plate structure which includes a centralplane sided portion A with an enlarged header enclosing structure B extending along each of two'opposite edges of the plate, and including or surrounding a pair of spaced header structure. It will be understood that the enlarged structure constitutes a reenforcement for the plate, providing parallel reenforcements along each of two opposite edges. It will further be understood that these edge enlargements constitute side walls or limit members which prevent the unintended lateral escape of material undergoing treatment, and define a longitudinally extending trough.

2 Claims. (Cl. 257-256) With particular reference to the structure shown, I illustrate headers l and 2. In Figure 3 these headers are illustrated as cylindrical in cross-section. In the form of Figure '6 these headers, indicated at la or 2a. are shown as rectangular in form. 3 indicates an inlet extending to the header I, and 4 indicates an outlet extending from the header 2. So far as the structure is concerned, the relationship can be reversed and each of the members 3' or 41 can be used either as an inlet or as an outlet. For convenience of description, however, I will call the member 3 the inlet and the member 4 the outlet.

The headers are connected by a system of evaporator tubes or ducts which are arranged in parallel. These tubes, indicated at 5, are preferably rectangular incross-section, having opposite plane walls 6 and I, which are parallel with the later described plane face of the plate, and which are connected by side walls 8 and 5. Each evaporator duct 5 is provided with. a bend I0 connecting an initial length H with an intermediate length l2. The opposite end of the intermediate length I2 is connected by a bend IS with a terminal length I4. Whereas these ducts may be arranged in various ways, I find it advantageous to have the intermediate lengths I2 extend in parallel along the length of the plate. The initial lengths I l are shown a extending generally perpendicularly from the header 1. whereas the final lengths [4 are shown as extending generally perpendicularly to the header 2. It will be understood that the outer surface of all of the tube walls 6 are formed or constrained to a single common plane, the same being true of the outer surfaces of the opposite walls I.

I have described an evaporator structure, and it will be understood that a volatile refrigerant in liquid form, or, at least, only partly evaporated, may be delivered to the header I along the inlet duct or tube 3. The refrigerant then passes in parallel through the evaporator ducts 5 to the opposite header 2, and the partly or completely evaporated refrigerant escapes through the outlet 4. Any suitable means, not herein shown, may be employed for circulating or cycling a volatile refrigerant through the above described evaporator and header structure. I may employ any suitable mechanical compressor-condenser assembly, or I may employ an other suitable means for maintaining the desired flow of the volatile refrigerant through the evaporator ducts 5.

In order to provide the final plate, I house or enclose the above described evaporator structure in an outer housing. I illustrate, for example,-

opposite plate walls 2t and it which extend to and are connected to header surrounding housings or members 22 and 23. Each such header housing is shown as generally rectangular in cross-section. I find it practical and emcient to form the plate and header structure by employing unitary sheets which extend from side to side of the plate. Thus the plate wall ill is continuous with and forms part of a single sheet of material which is bent to form corners M, 25 and 26, and which terminates in an outward flange El. The plate wall it is similarly formed, with angles or corners 24a, 25a and 26a and a terminal flange 21a. The flanges 2'17 and his are welded or otherwise secured in liquid and gas-tight relationship. Corresponding flanges 29 and 29a, at the ends of the plate, are similarly welded. The end result is a plate structure, surrounding the evaporator, which is liquid and gas-tight, in which both the headers i, 2, and the evaporator ducts b are enclosed.

I may use one or more vacuum fittings 3% through which the air in the interior of the plate may be partly exhausted. As the air is withdrawn, the difierential of pressure between the outside atmosphere and the inside of the plate is effective to urge the walls 2d and 2H firmly against the opposed outer plane surfaces of the duct walls 6 and i. It will be understood that, before assembling the surrounding plate structure, the ducts ii, if not already true, are carefully trued, so that the outer surfaces of the walls 65 and "i come very close to lying in a single plane. As

the air is exhausted from inside of the plate, the

thrust of the atmospheric air is effective to lock the sheets or walls 2d and iii firmlyagainst the opposite faces of the ducts 5. The resultis a smooth-faced, true-surfaced plate, which is plane from end to end, but which is reenforced by an. enlargement or a thickening along each of two opposite edges. The thickening or enlargement performs the double function of reenforcing and truing the plate and of serving as a limit or wall to prevent the undesired lateral escape'of material across the edges of the plate, when the plate is used in a generally horizontal or somewhat inclined position for the handling or conveying of material in connection with or during the freezing operation.

It will be realized that, whereas, I have described and illustrated a practical and operative device, nevertheless, many changes may be made in the size, shape, number and disposition of parts without departing from the spirit of my invention. I therefore wish my description and drawings to be taken as in a broad sense illustrative or diagrammatic, rather than as limiting me to my precise showing.

The use and operation of my invention are as follows:

The above described plate may be used in a wide variety of sizes and shapes. A useful application of the invention is to a plate which is substantially longer than it is wide. Such a plate may, for example, be employed as a conveyor or a chute for material undergoing treatment. It may be positioned, either horizontally or at an angle to the horizontal. Material may be conveyed gravitally or mechanically along the length of the plate.

The employment of two parallel headers, with the connecting sequence of ducts I, constitutes, with the outside plates, 9. strong, reenforced and substantially rigid structure, which will maintain a true plane surface throughout a very substantial length.

It will be understood, of course, that these plates may be used in groups, arranged in parallel or in series, with any suitable system or means for circulating or cycling a refrigerant, preferably a volatile refrigerant, through the ducts B.

A practical application of my invention is to employ one or more of the above described plates, set at an angle to permit or cause a gravital movement of material to be cooled or frozen. Where a liquid such as milk is being cooled, a slight inclination may be sufficient, but where foodstuffs or liquids are being frozen, a substantial angle may be necessary in order to maintain gravital feed or movement of solids.

I claim:

1. In a cold plate adapted to maintain a substantially true plane surface over a substantial area and throughout wide temperature variations, an outer housing including spaced, parallel plane flexible sheet metal top and bottom walls sealed together about their side and end edges, an evaporator structure in the space surrounded by said walls, including headers extending generally parallel and adjacent the opposite side edges of the plate and evaporator tubes extending between said headers, each said evaporator tube having an end portion extending from one header, an opposite end portion extending from the other header a, a connectingintermediate portion, the evaporator tubes having throughout their length fiat parallel surfaces opposed to'the inner faces of both said top and bottom walls, the evaporator tubes being uniformly spaced, the ends of each tube being uniformly offset, said tubes being of generally uniform length and being bent intermediate their end portions, said bends being generally aligned, the end portions decreasing in length inwardly from each of the end edges of the plate, whereby each tube is adapted to flex in response to temperature changes without varying the distance between headers or the distance between said top and bottom walls, an inlet pipe extending to one header and an outlet pipe extending to the other said header, the headers and evaporator tubes constituting reinforcements for the hous ing, and means for maintaining a less than atmospheric air pressure in the housing whereby, in response to such pressure differential, the flexible top and bottom walls are firmly held against the opposed flat surfaces of the evaporator tubes.

2. The structure of claim 1 characterized by and including enlarged opposite plate edge portions extending along the side edges of the plate, the headers being located in said enlarged portions.

HERMAN W. KLEIST.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

